Time reminding machine

ABSTRACT

A time reminding machine wherein this insulating members, such as business cards, are selectively inserted between normally closed spring contracts. The contracts are sequentially enabled at intervals, such as one-quarter or one-half hour, by a time keeping device to actuate an annunciator.

United States Patent Buckland, Jr. et al.

[ Dec. 17, 1974 TIME REMINDING MACHINE Inventors: William J. Buckland, Jr., Merrick;

Kevin C. ODaly, Levittown, both of N.Y.

Product Potentials Inc., Hicksville, N.Y.

Filed: Feb. 5, 1973 Appl. No.: 329,852

Assignee:

US. Cl. 340/3094, 340/3091 Int. Cl. G08b 7/00 Field of Search 340/3094, 309.5, 309.1;

References Cited UNITED STATES PATENTS 11/1888 Trafford 340/3094 R 783,399 2/1905 Blank ZOO/61.19 1,999,803 4/1935 Carney 340/3094 R 3,255,442 6/1966 Kimberlin 340/3094 R Primary Examinerl-larold l. Pitts Attorney, Agent, or Firm-Shenier & OConnor [57] ABSTRACT A time reminding machine wherein this insulating members, such as business cards, are selectively inserted between normally closed spring contracts. The contracts are sequentially enabled at intervals, such as one-quarter or one-half hour, by a time keeping device to actuate an annunciator.

48 Claims, 11 Drawing Figures BUZZ PATENTEDBECIYW 3.855 588 saw u 55 g TIME REMINDING MACHINE BACKGROUND OF THE INVENTION Time reminding machines of the prior art employ a rotating drum or drums. Cards are inserted into appropriate receptacles carried by the drum, or mechanical dogs mounted at the periphery of the drum are manually actuated. Such devices are bulky, heavy, easily damaged, and subject to loss of the time keeping function if the drum is accidentally displaced by a person brushing by.

SUMMARY OF THE INVENTION One object of our invention is to provide a time reminding machine which operates electrically and has no mechanically rotating drum.

Another object of our invention is to provide a time reminding machine wherein thin insulating members such as business cards are selectively inserted between pairs of normally closed spring contacts.

Still another object of our invention is to provide a time reminding machine which may be set to any desired minute of the hour rather than merely to such intervals as A or 7% hour.

A further object of our invention is to provide a time reminding machine which is small in size, light in weight, and of simple and inexpensive construction.

Other and further objects of our invention will appear from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings which form part of the instant specification and which are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views:

FIG. 1 is a plan view ofa first embodiment of our invention;

FIG. 2 is a side view taken along the line 22 of FIG. 1 with parts broken away;

FIG. 3 is a sectional view taken along the line 3--3 of FIG. 2;

FIG. 4 is a sectional view taken along the line 4-4 of FIG. 3;

FIG. 5 is a sectional view taken along the line 5-5 of FIG. 1;

FIG. 6 is a schematic sectional view taken along the line 6-6 of FIG. 5;

FIG. 7 is a plan view of a second embodiment of our invention;

FIG. 8 is a sectional view taken along the line 8-8 of FIG. 7;

FIG. 9 is a schematic view showing the time keeping circuit of the embodiment of FIG. 7;

FIG. 9a is a diagrammatic view showing the arrangement of lamps for producing the numerical display of the embodiment of FIG. 7;

FIG. 10 is a schematic view showing the remaining electrical circuitry of the embodiment of FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now more particularly to FIGS. 1, 2, and 3 of the drawings, a housing includes a top plate 17, a bottom plate 17a and a side plate 17b. The top plate 17 is provided with a cutout for the face 14 ofa clock having a minute hand 14a and an hour hand 14b which may be either mechanically or electrically driven. Top plate 17 is also provided with cutouts for an indicator lamp l8 and a reset button 19. Along the Iefthand margin of plate 17 are slots for a series of twelve manually operable slide switches indicated generally by the reference numeral 20. Along the righthand margin of plate 17 are slots for a further series of 12 manually operable slide switches indicated generally by the reference numeral 21. A calendar pad 22 is centrally positioned on top plate 17. Along the left hand margin of the calendar are time indicia 22a for each half hour running from 8:00 to 1:30 which are aligned with the slide switches 20. Along the right hand margin of the calendar are time indicia 22b for each half hour running from 2:00 to 7:30 which are aligned with the slide switches 21. Each slide switch has an operating button. such as 20a and 20b, which is adapted to be moved left and right. The operating buttons are normally positioned adjacent the margins of top plate 17 but may be moved toward the calendar pad when an alarm is desired at an appropriate half-hour interval. For example, in FIG. 1, switch 20a has been actuated; and an alarm will be sounded at 12:00. Similarly, for the switches 21, an alarm will be sounded at 3:30.

In addition to the operating buttons, such as 20a or 20b, each switch includes a slide, such as 23a or 23b, and a thin knife-like depending portion, 240 or 24b, formed of an insulating material such as plastic. If desired the actuating button 20a, the slide 23a, and the knife-like depending portion 24a may be integrally formed of plastic. Slides 23a and 23b operate in a clearance space provided between the lower surface of top plate 17 and the upper surface of a slotted slideretaining member 17d.

Disposed parallel to the side wall 17b is an upstanding contact-supporting member 17c secured to the bottom plate 17a. A U-shaped spring contact member 25 is mechanically and electrically secured to member 170. Spring contact members 25a and 25b are electrically isolated from member by insulating members 26a and 2611, respectively. For each of the switches, the pairs of contact fingers are normally closed. Thus finger 25a normally contacts one leg of U-shaped member 25; and finger 25b normally engages the other leg of U- shaped member 25. The ends of each pair of contacts are flared outwardly in order to tolerate some misalignment between each pair of contact fingers and the depending knife edges 24a and 24b of the slide switches. As may be seen by reference to FIGS. 1, 3, and 4, when operating button 20a is moved toward the calendar, insulating knife member 24a separates finger 25a from one leg of contact member 25, thus opening the normally closed contacts. As may be seen by reference to FIGS. 2 and 3, the contacting elements of the switches are staggered in a vertical plane. For example, the contacts for the 12:00 and 12:30 switches are disposed in a lower plane which also contains the contacts for the 10:00 and 10:30 switches; while the contacts for the 11:00, 11:30, 1:00, and 1:30 switches are all disposed in an upper plane. The purpose of this staggering of contacts of adjacent pairs of switches is to afford clearance between contact finger 25a for the 12:00 switch and the contact finger for the 11:30 switch and to afford clearance between contact finger 25b for the 12:30 switch and the contact finger for the 1:00 switch.

Referring now to FIG. 5, the minute hand 14a is mounted for rotation on a shaft 15a; and the hour hand 14b is mounted on a hollow shaft 15b through which the minute hand shaft 15a coaxially extends. Secured to the back surface of the clock face 14 is an insulating commutator disc 28 having 24 equal conductive segments electrically isolated from one another. In FIGS. 5 and 6 only twelve commutator segments have been shown such as 28a, 28b, 28f, 28g, and 28!. Correspondingly, only 12 of the 24 pairs of switch contacts have been shown such as 25a, 25b, 25f, 25g, and 251. An annular ring of insulating material 16 is press fit on the hollow hour hand shaft b. A brush carrying member 27 is press fit on the insulating ring 16. Member 27 carries a pair of brush arms 27a and 27b. Secured to arm 27a is a brush 27c; and secured to arm 27b is a brush 27 d. The brushes 27c and 27d engage the commutator disc at points which are spaced apart a distance appreciably greater than the insulating gap between adjacent commutator segments but appreciably less than the length of a commutator bar. Thus the pair of brushes will bridge across the insulating gap between adjacent segments; but will for an appreciable period engage the same commutator bar. For example, with 24 intervals, each interval will subtend 15. The insulating gap between adjacent segments may be 25; and each commutator segment will subtend 12.5". The spacing between brushes 27c and 27d is preferably half the 15 interval or 7.5. This affords a 5 period during which the brushes engage adjacent segments and also a 5 period during which the brushes engage the same segment. A further brush 29 bears against the side of member 27. Brush 29 is supported on an insulating post 29a which is secured to the back surface of the clock face 14.

Referring now to FIG. 6, each of the segments of commutator 28 is connected to a corresponding leaf spring contact of a slide switch. Thus segment 27a is connected to contact member 250; segment 28!; is connected to contact 2517. The common U-shaped members 25 of each of the slide switches are grounded by virtue of their connection to the chassis member 170. The negative terminal of a source of potential 32 is grounded; and the positive terminal thereof is coupled through a resistor 30 to slip ring brush 29. Brush 29 is also connected to the base of an n-p-n transistor 31, the collector of which is connected to the positive terminal of battery 32. The emitter output of transistor 31 is coupled through a buzzer 33 to ground and is also applied to the setting input of a bistable flip-flop 34. The output of flip-flop 34 is coupled through lamp 18 to ground. The positive terminal of source 32 is coupled through a normally open, manually-operable reset switch 19 to the resetting input of flip-flop 34.

In operation of the embodiment of FIGS. 1 through 6, slide switches 20 and 21 are actuated in accordance with the times of various appointments. Notes may be entered on the calendar in the spaces provided to indicate the nature of the appointment. The setting of these slide switches causes an associated insulating knife edge such as 240 to be inserted between the normally closed spring contact fingers of the slide switch, thus open circuiting the switch..

The segments of commutator 28 are normally maintained at ground potential by the slide switches. Thus brushes 27c and 27d are normally maintained at ground potential, which in turn maintains output brush 29 and the base of transistor 31 at ground potential. Since the emitter output of emitter follower 31 is also at ground potential, buzzer 33 is quiescent; and flip-flop 34 is not set. Thus lamp 18 is extinguished.

In FIG. 6 only twelve intervals have been provided rather than 24 as indicated in FIG. 1. Accordingly, switch 251 may correspond to 11:00, switch 25a may correspond to 12:00, and switch 25b may correspond to 1:00. Assume that the 12:00 switch 25a has been actuated so that these contacts are open. Since in FIG. 6 only twelve intervals are provided, each interval will subtend 30 and represent 1 hour. Brushes 27c and 27d are preferably spaced apart by half the interval length, or 15. The insulating gap between adjacent segments may be 5; and each segment will thus subtend 25. In the position of brushes 27c and 270' shown, the time is 1 1:50. Brush 27c engages segment 28a; but since switch 25a is open, brush 27c is not effective to maintain the base of transistor 31 at ground potential. However, brush 27d engages segment 28 l; and since switch 251 is closed, brush 27a is effective to maintain the base of transistor 31 at ground. As the brush-bearing member 27 rotates counterclockwise in the direction of the arrow, brush 27d will disengage segment 28! at 12:00. At this point brush 27d engages an insulating strip of commutator 28 which separates segments 28a and 281. At this time there is no current path through either of brushes 270 or 27d to ground. Current through biasing resistor 30 now flows into the base of transistor 31', and the emitter of transistor 31 rises to a potential slightly less than that provided at the positive terminal of battery 32. This actuates buzzer 33 and sets flip-flop 34, which in turn illuminates lamp 18.

If an attendant is within hearing distance of the buzzer, he will go to the machine and throw the 12:00 switch operating button 20a to the left. This closes contacts 25a. Since brush 27c now lies well in engagement with segment 28a, the base and hence the emitter of transistor 31 will be returned to ground potential; and buzzer 33 will be rendered. quiescent. However lamp 18 will remain illuminated, since flip-flop 34 is a bistable device and maintains the last state to which it was set or reset. The attendant will now note the nature of the appointment written on calendar 22 in the 12:00 position and take appropriate action. Once this action has been taken, the attendant may then momentarily depress the spring-loaded reset button 19 which resets flip-flop 34 and extinguishes lamp 18. If no attendant is within hearing distance of buzzer 33, then it will continue to sound for 40 minutes until 12:40. At this time the leading brush 27c will engage segment 28b; and the normally closed switch 25b will return the base and hence the emitter of transistor 31 to ground potential. Buzzer 33 will be rendered quiescent. However, lamp 18 will remain illuminated until an attendant momentarily depresses the spring-loaded reset button 19 to reset flip-flop 34.

It will be appreciated that where commutator 28 has 24 segments, buzzer 33 will sound for at most twenty minutes out of each half hour interval. If desired, 48 slide switches and corresponding commutator segments may be provided at 15 minute intervals each corresponding to 7.5 rotation of the hour hand shaft. Brushes 27c and 27d are preferably spaced apart by 3.75"; the insulating gap between adjacent segments may be approximately 1.25; and each segment would accordingly subtend approximately 6.25. Buzzer 33 would then sound for at most ten minutes out of each fifteen minute interval.

Referring now to FIG. 7, we provide an electronic time keeping device with a digital indicator indicated generally by the reference numeral 14. The indicated time is AM 8:17:46". Beneath the seconds display is a manually-operable advance button 37. Beneath the minutes display is a manually-operable advance button 38; and beneath the hours display is a manuallyoperable advance button 39. Along the left hand margin of top plate 17 are time indicia 22a for each quarter hour running from 7:00 to 12:45. Along the right hand margin of the top plate are time indicia 22b for each quarter hour running from 1:00 to 6:45. lndicia 22a cooperate with 24 horizontally-extending slots indicated generally by the reference numeral 20; and indicia 22b cooperate with 24 horizontally-extending slots indicated generally by the reference numeral 21. For example, slot 20a corresponds to a time of 12:00; and slot 20b corresponds to the time 12:15.

Referring now to FIGS. 7 and 8, slots 20 and 21 are adapted to receive a business card 24 which is formed of an insulating material such as heavy paper or light cardboard. Aligned with each slot is a pair of normally closed spring contact fingers carried by the bottom plate 17a. When card 24 is inserted in slot 20b, contact finger 25b is separated from one leg of U-shaped member 25 thus open circuiting the pair of contacts. Spring contact finger 25a normally engages the other leg of U- shaped member 25 unless another card such as 24 is inserted in slot 20a. The U-shaped spring contact member 25 electrically engages the conducting bottom wall 170. Spring contact fingers 25a and 25b are electrically isolated from bottom wall 17a by respective insulating members 26a and 26b. As may be seen by reference to FIG. 7 the contacts for adjacent pairs of slots are staggered. Thus the contacts for the 12:00 and 12:15 slots lie in the same plane as the contacts for the 1 1:00 and 11:15 slots. The contacts for the 11:30, 11:45, 12:30, and 12:45 slots all lie in the same plane. This affords an insulating clearance between the spring fingers of the 12:15 and 12:30 slots between the spring fingers of the 12:00 and 11:45 slots.

Referring now to FIG. 9, a wall plug 33 is connected to a source of 60 Hz alternating current of approximately 115 volts. Plug 33 is connected to the primary winding of a step-down transformer, indicated generally by the reference numeral 33a, having a secondary winding one terminal of which is grounded and the other terminal of which is connected to a power supply 32 and to the input of a trigger circuit 34. The output of trigger circuit 34 indexes a binary counter 35 providing six outputs and capable of counting to 63. The 1 and 2 outputs of counter'35 are not used. The 4, 8, l6, and 32 outputs of counter 35 are coupled to the input of an AND circuit 35a. The output of AND circuit 35a is applied to a network 35b providing a time delay of 1 millisecond. The output of delay network 35b resets counter 35 to 0. The output of AND circuit 35a is connected to one input of an OR circuit 36. The output of OR circuit 36 indexes a ten-stage ring counter 42 and is also connected to the input of a divide-by-two flipflop 41 providing an output at terminal 41a. Ring counter 42 has ten output terminals, providing the counts of 0 through 9, which are coupled to the input of a translator 57. The 0 output of counter 42 is connected to a terminal 42a which indexes a six-stage ring counter 43. Ring counter 43 has six output terminals, providing the counts of 0 through 5, which are coupled to a translator 58. A five position selector switch 43a is mounted in the back wall as may be seen by reference to FIG. 7. The armature of switch 43a may be manually set to any desired contact from 1 to 5. The 1 output of counter 43 is connected to the 1 contact of switch 43a. Similarly, the 2 through 5 outputs of counter 43 are connected to corresponding contacts of selector switch 43a. The armature of switch 43a is connected to a terminal 43b. The 0 output of counter 43 is coupled through a differentiating capacitor 45 to one input of an OR circuit 46. The output of OR circuit 46 is connected to a terminal 46a which indexes a IO-stage ring counter 47. Ring counter 47 has ten output terminals, providing the counts of 0 through 9, which are coupled to a translator 59. The 0 output of counter 47 indexes a six-stage ring counter 48. Ring counter 48 has six output terminals, providing the counts of 0 through 5, which are coupled to a translator 60. The 0 output of counter 48 is coupled through a differentiating capacitor to one input of OR circuit 51, the output of which indexes a 10-stage ring counter 52. Counter 52 has ten output terminals, providing the counts of 0 through 9, which are coupled to the input of a translator 61. The 0 output of counter 52 sets a bistable flipflop 53. The output of flip-flop 53 is coupled to a translator 62 and to one input of each of AND circuits 54 and 56. The 2 output of counter 52 is connected to the other input of AND circuit 54. The AND circuit 54 provides an output at terminal 54a representing 12 oclock which drives a divide-by-two flip-flop 55. The output of flip-flop 55 is coupled to a translator 63. The 3 output of counter 52 is connected to the other input of AND circuit 56. The AND circuit 56 provides an output indicating 13 o'clock which is applied to a network 56a providing a time delay of l millisecond. The output of delay network 56a resets flip-flop 53 and resets counter 52 to l.

The positive output terminal 32a of the directcurrent power supply is connected to one contact of each of switches 37, 38, and 39. The other contact of switch 37 is grounded through a resistor 40a and is connected through a differentiating capacitor 40 to the other input of OR circuit 36. The other contact of switch 38 is grounded through a resistor 44a and is coupled through a differentiating capacitor 44 to the other input of OR circuit 46. The other contact of switch 39 is grounded through a resistor 49a and is coupled through a differentiating capacitor 49 to the other input of OR circuit 51. Translators 57 through 61 each provide seven outputs for actuating the seven lamps of a numerical display. The outputs of a translator 57 drive the seconds display. The outputs of translator 58 drive the tens-of-seconds display. The outputs of translator 59 drive the minutes display. The outputs of translator 60 drive the tens-of-minutes display. The outputs of translator 61 drive the hours display. The outputs of translator 62 drive the tens-of-hours display. The positive output terminal 32a of the power supply continuously energizes two small lamps which indicate a colon between the hours and minutes display and continuously energizes two further small lamps which indicate a colon between the minutes and seconds display. Terminal 32a further continuously energizes a lamp or lamps which display the letter M to the left of the tensof-hours display. The outputs of a translator 63 are coupled to a display indicator immediately to the left of the M display which selectively provides the letters A or P.

FIG. 9a shows the arrangement of lamps for each of the variable indicators of display 14 including the six indicators for hours, minutes, and seconds and the additional indicator for A or P which cooperates with the constant M indicator to provide the resultant display of either AM" or PM. Lamps 1, 2 and 3 extend horizontally at the bottom, middle, and top, respectively, of the indicator. Lamps 4 and 5 extend vertically along the left-hand margin of the indicator with lamp 4 being uppermost and lamp 5 being lowermost. Lamps 6 and 7 extend vertically along the right-hand margin of the indicator with lamp 6 being uppermost and lamp 7 being lowermost.

Translator 63 provides only six outputs for lamps 2 through 7, since lamp 1 is not required for the AIP indicator. Terminal 32a constantly excites lamps 2 through 6 of the A/P indicator. Flip-flop 55 selectively drives lamp 7 of the All indicator. Translator 62 provides only two outputs. Flip-flop 53 selectively excites lamps 6 and 7 of the tens-of-hours indicator. For this indicator, lamps 1 through 5 may be omitted, since no is displayed for the tens-of-hours for time between 1:00:00 and 9:59:59.

Preferably translator 61 is so constructed that a 1 output from counter 52 illuminates lamps 4 and of the hours display. Preferably translator 60 is so constructed that a 1 output from counter 48 illuminates lamps 6 and 7 of the tens-of-minutes display. Preferably translator 59 is so constructed that a 1 output from counter 47 illuminates lamps 4 and 5 of the minutes display. Preferably translator 58 is so constructed that a 1 output from counter 43 illuminates lamps 6 and 7 of the tens-of-seconds display. Preferably translator 57 is so constructed that a 1 output from counter 42 illuminates lamps 4 and 5 of the seconds display.

The time-constant of differentiating capacitor 40 in conjunction with the input resistance of OR circuit 36 may be one millisecond. The time-constant of differentiating capacitors 44 and 49 in conjunction with the input resistances of OR circuits 46 and 51 may each be one millisecond. The time-constants of differentiating capacitors 45 and 50 in conjunction with the input resistances of OR circuits 46 and 51 may each be I millisecond.

In operation of the time keeping circuit of FIG. 9, trigger circuit 34 provides a positive output during each positive half cycle of the alternating-current voltage excursion across the secondary winding of step-down transformer 33a. Thus binary counter 35 is indexed at a rate of 60 times per second. Counter 35 is successively indexed from the count of 0, where all six outputs are at ground potential, to the count of 59, where the 4 output is at ground potential and the remaining five outputs are positive. When the count of 60 is reached, the four most significant outputs are positive and the two least significant outputs are at ground potential. The AND circuit 35a now provides an output. One millisecond later, delay network 35b provides an output which resets counter 35 to 0; and the output of AND circuit 35a drops to ground potential. The one millisecond rectangular output pulse of AND circuit 35a is also coupled through OR circuit 36 to index the seconds counter 42. Each time ring counter 42 cycles through the count of 0, counter 43 is indexed. Each time that counter 43 cycles through the count of 0, counter 47 is indexed through differentiating capacitor 45 and OR circuit 46. Each time that counter 47 cycles through the count of 0, counter 48 is indexed. Each time that counter 48 cycles through the count of 0, counter 52 is indexed through differentiating capacitor 50 and OR circuit 51.

When the hours counter 52 cycles through the count of 0, as in going from 9 o'clock to 10 o'clock, flip-flop 53 is set. At 12 oclock, AND circuit 54 provides an output which indexes divide-by-two flip-flop 55 to change the display from AM to PM or from PM to AM. At 13 oclock, AND circuit 56 provides an output. I millisecond later, delay network 56a provides an output which resets flip-flop 53 and resets counter 52 to 1, thus changing the hours display from 13 oclock to 1 oclock and causing the output of AND circuit 56 to drop to ground potential. Hence AND circuit 56 provides a rectangular output pulse of one millisecond duration.

The normally-open spring-loaded push button switches 37, 38, and 39 are manually depressed or tapped at any desired rate to advance the seconds, minutes, and hours and thus set the time indication to its proper value. Preferably the seconds are set first, since there is always a carry over from the tens-of-seconds into the minutes. The minutes are then set, since there is a carry over from the tens-of-minutes into the hours. Finally the hours may be set. It will be appreciated that as many as 23 depressions of the hours setting button 39 may be required in order properly to set the AM/PM display which is indexed each twelve hours. Buttons 37 and 38 need not be depressed or tapped more than fifty-nine times each. The provision of the differentiating capacitors 40, 44, 49, 45 and 50 insures that l millisecond pulses may be coupled through OR circuits 36, 46, and 51 both from the time keeping counters 35, 43, and 48 and from the manual advance switches 37, 38, and 39 without interferences, since there is little likelihood of pulse overlap. The pulses from the differentiating capacitors are decaying exponentials of a generally triangular shape.

Referring now to FIG. 10, the output of flip-flop 53 is coupled to an inhibiting input of AND circuits 65, 66, and 67 and to an enabling input of AND circuits 68, 69, and 54. The 0 output of counter 52 is connected to an enabling input of AND circuit 68. The 1 output of counter 52 is connected to an enabling input of AND circuits and 69. The 2 output of counter 52 is connected to an enabling input of AND circuits 66 and 54. The 3 output of counter 52 is connected to an enabling input of AND circuit 67. The output of AND circuit 65 at terminal 65a represents 1 oclock. The output of AND circuit 66 represents 2 o'clock. The output of AND circuit 67 represents 3 o'clock. The 4 through 9 outputs of counter 52 respectively represent 4 oclock through 9 oclock. The output of AND circuit 68 represents ten o'clock. The output of AND circuit 69 represents l 1 oclock. The output of AND circuit 54 at terminal 54a represents 12 oclock.

The 5 output of minutes counter 47 is connected to one input of each of AND circuits 70a and 70b. The 1 output of counter 48 is connected to the other input of AND circuit 70b; and the 4 output of counter 48 is connected to the other input of AND circuit 70a. The outputs of AND circu'its 70a and 70b are coupled to the inputs of an OR circuit 70c, the output of which indexes a divide-by-four ring counter 71. Counter 71 has four output terminals representing the counts of through 3. The 0 output of counter 48 resets counter 71 to 0; and the 3 output of counter 48 resets counter 71 to 2.

For each of the 48 card slots 21 and 22, we provide a corresponding AND circuit 72, of which only eight have been shown to simplify the description. The AND circuits 72a, 72b, 72and 72d correspond to the slots for times 12:00, 12:15, 12:30, and 12:45, respectively. The AND circuits 72e, 72f, 72g, and 72h correspond to the slots for times 1:00, 1:15, 1:30, and 1:45, respectively. The 12 oclock terminal 54a is connected to one input of each of AND circuits 72a through 72d. The l oclock terminal 65a is connected to one input of each of AND circuits 72e through 72h. The 0 output of ring counter 71 is connected to a second input of each of AND circuits 72a and 72:2. The 1 output of counter 71 is connected to a second input of each of AND circuits 72b and 72f. The 2 output of counter 71 is connected to a second input of each of AND circuits 72c and 723. The 3 output of counter 71 is connected to a second input of each of AND circuits 72d and 72h. The positive terminal 32a of the power supply is connected through a resistor 73a to a third input of AND circuit 72a. Positive terminal 32a is similarly connected through respective resistors 73b through 73h to a third input of AND circuits 72b through 7211. The third input of AND circuit 72a is normally grounded through spring contact 25a which cooperates with slot a. Similarly the third input terminals of AND circuits 72b through 72h are normally grounded through spring contacts b through 25h respectively.

The outputs of AND circuits 72a through 72h are all connected to one input of an AND circuit 75, which receives a second input from a bistable flip-flop 82. The output of AND circuit 75 is connected to one input of each of OR circuits 88a and 88b and to the setting input of a bistable flip-flop 34. The output of AND circuit 75 further indexes a divide-by-two flip-flop 74 having a low output impedance. The output of divide-by-two flip-flop 74 is coupled to ground through the actuating winding 77 of a relay having single-pole double-throw contacts 77a. The output of flip-flop 74 is further coupled through a bilateral gate 89 to a holding circuit 90, comprising a bistable flip-flop having a high output impedance. Holding circuit 90 drives an enabling input of an AND circuit 76b and an inhibiting input of an AND circuit 76a. The outputs of AND circuits 76a and 76b are coupled to an OR circuit 76c, the output of which is applied to the setting intput of flip-flop 82.

Terminal 46a, which provides indexing pulses to minutes counter 47, is also connected to the indexing input of a lS-stage ring counter 8]. Counter 81 has fifteen output terminals providing the counts of 0 through 14. The output of OR circuit 700 resets counter 81 to 0. The output of OR circuit 880 is connected through buzzer 33 to ground; and the output of OR circuit 88b is connected through lamp 18 to ground. Positive terminal 32a is coupled through reset switch 19 to the resetting input of flip-flop 34. The output of flip-flop 34 is connected to one input of each of AND circuits 86 and 87. The output of AND circuit 86 is connected to the other input of OR circuit 88b; and the output of AND circuit 87 is connected through a resistor 87a to the other input of OR circuit 88a. Output terminal 41a of divide-by-two flip-flop 41 is connected to the other input of AND circuit 86; and the 0 output terminal 42a of counter 42 is connected to the other input of AND circuit 87.

One line from wall plug 33 is connected to the armature of relay contacts 77a. The other line from wall plug 33 is connected to one terminal of a receptacle 78a and to one terminal of a receptacle 78b. As may be seen by reference to FIG. 7, receptacles 78a and 78b are mounted in the front wall of our machine. The normally-closed relay contact 77a is connected to the other terminal of receptacle 78b; and the normallyopen relay contact 77a is connected to the other terminal of receptacle 78a. The terminals of receptacle 78a are shunted by a neon glow lamp 79a connected in series with a resistor 79c. The terminals of receptacle 78b are shunted by a neon glow lamp 79b connected in series with a resistor 79d. As may be seen by reference to FIG. 7, glow lamps 79a and 79b are also mounted in the front wall of the machine. Also mounted in the front wall are a pair of 15 position selector switches 80a and 80b, the armatures of which may be manually set to any desired contact from 0 to 14. The 0 output of counter 81 is connected to the 0 contacts of switches 80a and 80b. Similarly, the 1 through 14 outputs of counter 81 are connected to corresponding contacts of selector switches 80a and 80b. The armature of switch 80a is connected through a differentiating capacitor 80c to an enabling input of AND circuit 76b; and the armature of switch 80b is connected through a differentiating capacitor 80d to an enabling input of AND circuit 76a. The 14 output of counter 81 is connected to one input of an AND circuit 83. Terminal 43b is connected through a differentiating capacitor 820 to the resetting input of flip-flop 82, to the other input of AND circuit 83, and to one contact of a single-pole double-throw slide switch 84. The output of AND circuit 83 is connected to the other contact of manually operable switch 84. The armature output of switch 84 enables bilateral gate 89 to conduct in both directions. As may be seen by reference to FIG. 7, vertically sliding switch 84 is mounted in the front wall between selector switches 80a and 80b. The time-constants of capacitors 80c, 80d, and 82a in conjunction with their associated load resistances may each be 1 millisecond.

As may be seen by reference to FIGS. 7 and 10, receptacle 78a, glow lamp 79a, and selector switch 80a are disposed on the left side of the front wall, while selector switch 80b, glow lamp 7%, and receptacle 78b are disposed on the right side of the front wall. Preferably selector switch 80a rotates clockwise for increasing counts in the manner shown for selector switch 80b. The counterclockwise rotation of switch 80a shown in FIG. 10 is only for the purpose of simplifying the interconnections between switches 80a and 80b.

In operation of the circuit of FIG. 10, AND circuits 65, 66, and 67 provide hour outputs for l, 2, and 3 0'- clock, respectively. The AND circuits 68, 69, and 54 provide hour outputs for 10, l 1 and 12 o'clock, respectively. The hour outputs for 4 through 9 oclock are directly provided by corresponding outputs of counter 52. The AND circuit 65 is required to distinguish l oclock from 11 o'clock; AND circuit 66 is required to distinguish 2 oclock from 12 oclock; and AND circuit 67 is required to distinguish 3 oclock from 13 o'clock. It will be recalled in conjunction with FIG. 9 that components 52 and 53 provide a 13 o'clock output from AND circuit 56 for l millisecond before being reset to 1 oclock by the output of delay network 56a.

On each hour, a counter 71 is reset to by the 0 output of counter 48. At minutes past each hour, counter 71 is indexed to 1 by AND circuit 70b through OR circuit 70c. At half past each hour, counter 71 is reset to 2 by the 3 output of counter 48. At 45 minutes past each hour, counter 71 is indexed to 3 by AND cir cuit 70a through OR circuit 70c.

All AND circuits 720 through 72h are normally disabled by virtue that the third input is maintained at ground by the normally closed contacts 25a through 2511. If, as in FIG. 8, a card is inserted into slot b, then contacts b will be open-circuited, and positive terminal 32a will enable the third input of AND circuit 72b through resistor 73b. When the time reaches 12:00, the positive signal at terminal 54a will enable the first input of AND circuit 72b. However, AND circuit 72b will not provide an output, since at this time only the 0 output of counter 71 is positive. When the time reaches 12:15, the 1 output of counter 71 becomes positive, thus enabling the second input of AND circuit 72b. Hence at 12:15, AND circuit 72b provides an output to AND circuit 75.

Assume for the moment that selector switches 80a and 80b are both set to 0. Ring counter 81 is indexed once each minute from terminal 460. Counter 81 is reset to 0 at 15 minutes and at 45 minutes past each hour by the output ofOR circuit 700. On each hour and at minutes past each hour, ring counter 81 will inherently cycle through 0 in response to the indexing input from terminal 46a. At 12:15, ring counter 81 will thus be reset to 0. At this time the armatures of switches 80a and 80b will both become positive, producing positive output pulses from capacitors 80c and 80d. irrespective of the state of holding flip-flop 90, one of AND circuits 76a and 76b will provide an output pulse which is coupled through OR circuit 760 to set flip-flop 82, thus enabling AND circuit 75. Accordingly, at 12:15, the output from AND circuit 72b is coupled through AND circuit 75, setting flip-flop 34, indexing flip-flop 74, energizing buzzer 33 through OR circuit 88a, and illuminating lamp 18 through OR circuit 88b.

Flip-flop 82 receives a reset pulse either 10, 20, 30, 40, or 50 seconds after each minute as governed by the position of selector switch 430. Thus if switch 43a is set to 1, terminal 43b will become positive 10 seconds after each minute. If, as shown in FIG. 9, switch 43a is set to 5, terminal 43b will become positive 50 seconds after each minute.

If between 12:15:00 and 12:15:50, an attendant removes card 24 from slot 20b in response to buzzer 33, then contacts 25b will close; AND circuit 72b will be disabled; and the output of AND circuit 75 will drop to ground. At 12:15:50, flip-flop 82 is reset by the pulse coupled through capacitor 82a from terminal 43b. This disables AND circuit 75 even though card 24 remains in slot 20b. The disabling of AND circuit 75, either at 12:15:50 by resetting of flip-flop 82 or at some earlier time between 12:15:00 and 12:15:50 by removal of card 24 from slot 20b, permits flip-flop 34 to control lamp 18 and buzzer 33. Flip-flop 34 was set at 12:15:00 and enables AND circuits 86 and 87. The signal at terminal 41a is coupled through AND circuit 86 and OR circuit 88b to lamp 18. Since divide-by-two flip-flop 41 is indexed once each second, lamp 18 will blink on for one second, off for one second, and on for one second again. The signal at terminal 42a is coupled through AND circuit 87, intensity-reducing resistor 87a and OR circuit 88a to buzzer 33. Buzzer 33 will thus emit a reduced intensity sound or beep" of one second duration once each 10 seconds. This serves to alert the attendant when he returns to the machine. Once flip-flop 34 is set, it will remain set until reset switch 19 is mementarily depressed.

Each time AND circuit provides an output, flipflop 74 changes state. This energizes relay winding 77 if it was previously de-energized, or de-energizes relay winding 77 if it was previously energized. Relay armature 77a is shown in the unenergized position of winding 77, where power is applied to receptacle 78b and glow lamp 79b is illuminated. When winding 77 is energized, relay armature 77a is drawn to its alternate position where power is applied to receptacle 78a and glow lamp 79a is illuminated. Our machine may thus be used as a timing device to control the application of power to some external electrical load such as a lamp. For example, assume that cards are inserted in the slots corresponding to 6:00, 11:00, 12:15, and 12:30; that immediately prior to 6:00 P.M., the relay armature 77a is in the position shown; and that the external load such as a lamp is plugged into the unenergized receptacle 78a. The lamp will be turned on at 6:00 P.M. and will be turned off at 11:00 P.M. The lamp will be turned on again at 12:15 A.M. and will be turned off again at 12:30 A.M. The lamp will remain off until 6:00 A.M. at which time it will again be turned on.

Our machine is not limited to operation at the fifteen minute intervals corresponding to the time indicia of the card slots. Instead switches 80a and 80b may be set other than to the 0 positions so that AND circuit 75 provides an output at any desired minute intermediate the standard 15 minute intervals. Assume, as shown in FIG. 10, that switch 80a is set to 3 and that switch 80b is set to 10. In the unenergized position of relay winding 77 shown, glow lamp 79b is illuminated to indicate not only the energized receptacle 78b but also the selector switch 80b which is operative to offset the time from the normal fifteen minute intervals of the slot indicia.

Assume slide switch 84 is in the position shown in FIG. 10. At 12:14, the 14 output of counter 81 partially enables AND circuit 83. At 12:14:50, the pulse from capacitor 820 is coupled through AND circuit 83 to enable bilateral gate 89. This causes holding flip-flop to be forced to the same state as flip-flop 74. When relay winding 77 is not energized, flip-flop 74 provides no output; and at 12:14:50 the output of holding flipflop 90 will be forced to ground potential irrespective of its previous state. This partially enables AND circuit 76a and disables AND circuit 761;. If a card 24 is in slot 20b, contacts 25b will be open; and the third input of AND circuit 72b will be enabled by positive terminal 32a through resistor 73b. At 12:15, AND circuit 72b will provide an output partially enabling AND circuit 75. However, at this time flip-flop 82 provides no output, since it was reset at 12:14:50. Three minutes after 12:15, there is at 12:18, counter 81 will provide a 3 output. Armature 800 will thus receive a signal which is coupled through capacitor 80c to AND circuit 76b. However, AND circuit 7611 will not provide an output, since it is disabled when the output of holding flip-flop 90 is at ground potential. 10 minutes after 12:15, that is at 12:25, counter 81 provides a output. The armature of switch 80b now receives a signal which is coupled through capacitor 80d, enabled AND circuit 76a, and OR circuit 76c to set flip-flop 82. Thus at 12:25, AND circuit 75 provides an output which indexes divide-by-two flip-flop 74, sets flip-flop 34, continuously illuminates lamp 18 through OR circuit 88b, and continuously actuates buzzer 33 with a high intensity through OR circuit 88a. The indexing of divide-by-two flip-flop 74 at 12:25 energizes winding 77, moving relay armature 77a to the alternate position where receptacle 78a is energized and glow lamp 79a is illuminated. 50 seconds subsequently at 12:25:50, a pulse from capacitor 82a resets a flip-flop 82, disabling AND circuit 75. However, flip-flop 34, which was set at 12:25, causes lamp 18 to blink on and off for one second intervals each and causes buzzer 33 to be actuated with reduced intensity for a one second interval once every ten seconds. At 12:29, counter 81 provides a 14 output which partially enables AND circuit 83. At 12:29:50, a pulse from capacitor 82a is coupled through AND circuit 83 to enable gate 89. Holding flipflop 90 is now forced to a positive output state, which disables AND circuit 76a and partially enables AND circuit 76b. This renders the armature of switch 80a effective to control the offset time within a subsequent fifteen minute interval governed by the card slot. If, for example, a second card is in the 12:30 slot, then at 12:30, AND circuit 72c will provide an output partially enabling AND circuit 75. However at this time. flipflop 82 provides no output. Three minutes later at 12:33, counter 81 provides a 3 output. The armature of switch 80a receives a signal which is coupled through capacitor 80c. enabled AND circuit 76b, and OR circuit 76c to set flip-flop 82. Thus at 12:33, AND circuit 75 provides an output which indexes flip-flop 74, continuously illuminates lamp 18, and continuously actuates buzzer 33 with a high intensity. Relay winding 77 is thus de-energized at 12:33, permitting armature 77a to return to the position shown, where receptacle 78b is energized and glow lamp 79b is illuminated. At 12:33:50, flip-flop 82 in reset; but flip-flop 34 causes lamp 18 to blink on and off and causes buzzer 33 to beep intermittently at reduced intensity. At 12:40, counter 81 provides a 10 output. Armature 80b will thus receive a signal which is coupled through capacitor 80d to AND circuit 760. However AND circuit 76a is disabled, since holding flip-flop 90 is still in a positive output state. At 12:44:50, AND circuit 83 enables gate 89; and the output of holding flip-flop 90 is forced to the ground potential state of flip-flop 74. This disables AND circuit 76b and partially enables AND circuit 76a. The armature of switch 80b is now effective to set flip-flop 82 at ten minutes after such subsequent quarter hour. It will be appreciated that if there is no card in the 12:45 slot, then AND circuit 72d will not provide an output at 12:45. Accordingly, the setting of flip-flop 82 at 12:55 will not produce an output from AND circuit 75. Flip-flop 82 is reset at 12:55:50.

If the total time interval between successive outputs from AND circuit 75 is fifteen minutes or greater, then switch 84 should be in the position shown; and the beginning and end of the time interval will always be governed by cards in two different slots. However where the total time interval between successive outputs from AND circuit 75 is 14 minutes or less, then it is possible that the beginning and end of the time interval may both occur within the quarter-hour period of a single card slot. For example, a fourteen minute interval from 12: 1 5 to 12:29 begins and ends within the quarter-hour period of the 12:15 card slot. But a 14 minute interval from 12:14 to 12:28 would be governed by cards in the 12:00 and 12:15 slots; while a 14 minute interval from 12:16 to 12:30 would be governed by cards in the 12:15 and 12:30 slots. For another example, a 1 minute interval from 12:14 to 12:15 would be governed by cards in the 12:00 and 12:15 slots. But a 1 minute interval from 12:13 to 12:14 would be governed by a single card in the 12:00 slot, while a one minute interval from 12:15 to 12:16 would be governed by a single card in the 12:15 slot.

Where the total time interval is 14 minutes or less and the interval begins and ends within the quarterhour period of a single card slot, then switch 84 must be actuated to its alternate position; and gate 89 will be enabled 50 seconds after each minute by the pulse from capacitor 82a. Assume that a card is in the 12:15 slot 20b, that the armatures of switches 80a and 80b are in the positions shown, that switch 84 is in its alternate position, and that flip-flops 74 and 90 are both in a positive output state prior to 12:15. Thus AND circuit 76b is partially enabled. At 12:15, AND circuit 72b provides an output; but AND circuit is disabled, since flip-flop 82 was reset at 12:14:50. At 12:18, counter 81 provides a 3 output which is applied through armature 80a, capacitor 80c, enabled AND circuit 76b, and OR circuit 760 to set flip-flop 82. Hence at 12:18, AND circuit 75 provides an output which indexes flip-flop 74, de-energizing winding 77. At 12:18:50, flip-flop 82 is reset, disabling AND circuit 75; and gate 89 is enabled to force holding flipflop to a ground potential output state. This partially enables AND circuit 760. At 12:25 counter 81 provides a 10 output which is applied through armature 80b, capacitor 80d, enabled AND circuit 76a, and OR circuit 76c to set flip-flop 82. Thus at 12:25, AND circuit 75 again provides an output. The time interval between successive outputs from AND circuit 75 at 12:18 and 12:25 is 7 minutes. The second output from AND circuit 75 at 12:25 indexes flip-flop 74, energizing winding 77. At 12:25:50, flip-flop 82 is reset, disabling AND circuit 75; and gate 89 is enabled to force holding flip-flop 90 to a positive output state.

Accordingly when switch 84 is in its alternate position, a single card slot can provide two distinct outputs from AND circuit 75 where the armatures of switches 80a and 80b are set to different positions. This feature may be used to advantage where two appointments are scheduled within the quarter-hour period of one of the card slots.

It will be seen that we have accomplished the objects of our invention. We have provided a time reminding machine which operates electrically and eliminates the mechanically rotating drum of the prior art. Our machine is compact, of low weight and of relatively simple and inexpensive construction. Thin insulating members such as business cards are selectively inserted between pairs of normally-closed spring contacts providing standard time increments as for example each half or quarter hour. Our machine is provided with selector switches so that the time may be set to any desired minute within the standard time intervals provided by the slide switches of FIG. 1 or the card slots of FIG. 7.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of our claims. It will be further obvious that various changes may be made in details within the scope of our claims without departing from the spirit of our invention. For example, AND circuit 75 may be omitted and the common output of AND circuits 72a through 72h directly connected to circuits 34, 74, 88a and 88b. The output of flip-flop 82 may then provide a variable voltage to resistors 73a through 73h in place of the fixed voltage from terminal 32a of power supply 32. With such alternate construction, the third inputs of AND circuits 72a through 72h will be disabled, irrespective of the state of the card slot switches a through 25h, until flip-flop 82 is set and its output becomes positive. It will also be appreciated that we may provide a 24 hour numerical display instead ofa l2 hour display in conjunction with an AM/PM indication. It will further be appreciated that we may use toggle switches instead of slide switches and that all switches may be normally open instead of normally closed. It is therefore to be understood that our invention is not to be limited to the specific details shown and described.

Having thus described our invention, what we claim l. A time reminding machine including in combination a plurality of normally-closed manually-operable switches, a time keeping device, an output circuit, and means responsive to the time keeping device for sequentially coupling each switch to the output circuit, 'said output circuit providing an output signal upon the coupling thereto of a switch which has been manually operated from its normal closed position to an open position.

2. A machine as in claim 1 wherein each switch comprises a pair of normally closed spring contacts and a thin insulating member adapted to be inserted therebetween.

3. A machine as in claim 1 wherein each switch comprises a pair of normally closed spring contacts, the machine further including a thin insulating member adapted to be inserted between the contacts of a selected pair.

4. A machine as in claim 3 wherein each group of two adjacent pairs of contacts comprises a centrally disposed U-shaped member, a first finger normally contacting one U leg of said member, and a second finger normally contacting the other U leg of said member.

5. A machine as in claim 4 wherein each U leg and its contacting finger flare apart adjacent their free ends to guide the insertion of the insulating member therebetween.

6. A machine as in claim 3 wherein alternate groups of two adjacent pairs of contacts are disposed. in alternate planes.

7. A machine as in claim 1 wherein the time keeping device includes an hour hand mounted on a shaft.

8. A machine as in claim 7 wherein the sequential coupling means includes a stationary commutator having a plurality of equally spaced conductive segments, means connecting each switch to a corresponding segment, and a brush mounted on said shaft and disposed to contact sequentially the segments of the commutator.

9. A machine as in claim 7 wherein the sequential coupling means includes a stationary commutator having a plurality of equally spaced conductive segments, and a pair of angularly spaced brushes mounted on said shaft and disposed to contact sequentially the segments of the commutator.

10. A machine as in claim 7 wherein the number of switches is N and wherein the sequential coupling means includes a pair of brushes mounted on said shaft and having an angular spacing of approximately l/N.

11. A machine as in claim 7 wherein the number of switches is N and wherein the sequential coupling means includes a stationary commutator having N equally spaced conductive segments, each segment subtending appreciably more than ISO/N", and the insulating gap between adjacent segments subtending appreciably less than ISO/N.

12. A machine as in claim 1 further including time indicia associated with each switch.

13. A machine as in claim 12 wherein the indicia provide half-hour increments.

14. A machine as in claim 12 wherein the indicia provide quarter-hour increments.

15. A machine as in claim 12 wherein the indicia are disposed in two columns of equal length.

16. A machine as in claim 15 wherein the indicia at the top of the left hand column represents a whole hour in the region from 6:00 to 9:00 and wherein the indicia at the top of the right hand column represents a whole hour in the region from l2100 to 3:00.

17. A machine as in claim 1 further including a top wall provided with a plurality of slots adapted to receive business cards.

18. A machine as in claim 1 further including a top wall provided with a calendar pad bearing time indicia.

19. A machine as in claim 1 further including a top wall, wherein the switches include manual operating members arranged in columns along the left hand and right hand margins of the top wall and disposed for movement left and right.

20. A machine as in claim 1 wherein the output circuit includes an aural annunciator and a visual annunciator.

21. A machine as in claim 1 further including an annunciator, a bistable circuit, means coupling the bistable circuit to the annunciator, means responsive to the output circuit for setting the bistable circuit, a manually-operable spring-loaded switch, and means responsive to operation of said switch for resetting the bistable circuit.

22. A machine as in claim 1 wherein the time keeping device includes a source of reference frequency, a plurality of cascaded counters, a plurality of display indicators, means coupling the reference source to the first counter of the cascade, and means coupling the final counters of the cascade to the respective display indicators.

23. A machine as in claim 22 wherein at least four numerical indicators provide a display in hours and minutes.

24. A machine as in claim 22 wherein at least six numerical indicators provide a display in hours and minutes and seconds.

25. A machine as in claim 22 wherein two numerical indicators display hours from 1 to 12 and wherein at least one further indicator selectively provides a display of ante and post meridian.

26. A machine as in claim 22 wherein the last counter of the cascade divides by two and is coupled to an indicator selectively providing the letters A and P, the machine further including an indicator providing a constant display of the letter M.

27. A machine as in claim 1 wherein the time keeping device includes a first divide-by-ten counter, a second divide-by-six counter, a third counter, means including a source of reference frequency for providing one pulse of fractional second duration each minute, means responsive to each one-per-minute pulse for indexing the first counter, means responsive to the first counter for indexing the second counter, means responsive to the second counter for providing one pulse of fractional second duration each hour, means responsive to each one-per-hour pulse for indexing the third counter, a first and a second manually-operable spring-loaded switch, means responsive to each operation of the first switch for providing a first pulse of fractional second duration, means responsive to each operation of the second switch for providing a second pulse of fractional second duration, means responsive to each first pulse for indexing the first counter, and means responsive to each second pulse for indexing the third counter.

28. A machine as in claim 27 wherein the means providing the one-per-minute pulses includes a fourth divide-by-ten counter, a fifth divide'by-six counter, means including a source of reference frequency for providing one pulse of short duration each second of time, means responsive to each one-per-second pulse for indexing the fourth counter, means responsive to the fourth counter for indexing the fifth counter, and means responsive to the fifth counter for providing the one-per-minute pulses, the machine further including a third manually-operable spring-loaded switch, means responsive to each operation of the third switch for providing a third pulse of fractional second duration, and means responsive to each third pulse for indexing the fourth counter.

29. A machine as in claim 27 wherein the third counter divides by 10, the machine further including a two state device and means responsive to the third counter for indexing the two state device.

30. A machine as in claim 1 wherein the sequential coupling means includes a plurality of logic circuits having at least one input, means connecting each switch to the input ofa corresponding logic circuit, and means responsive to the time keeping device for sequentially controlling the logic circuits.

3!. A machine as in claim 30 wherein the time keeping device includes an hours counter and a fractional hours counter, wherein each logic circuit has a second and a third input, and wherein the sequential controlling means includes means coupling the hours counter to the second input of each logic circuit and means coupling the fractional hours counter to the third input of each logic circuit.

32. A machine as in claim 1 wherein the time keeping device includes an hours counter, a fractional hours counter having a maximum count not less than two nor greater than 30, and a minutes counter having a maximum count not greater than 30 nor less than two, the product of the maximum counts of the fractional hours and minutes counters being equal to 60, and wherein the sequential coupling means includes means responsive to the hours and the fractional hours counters, the machine further including a first manually-operable selector switch having a number of positions equal to the maximum count of the minutes counter, means coupling the minutes counter to the selector switch, means responsive to the selector switch for providing a first master control signal, and first means responsive to the first signal for governing the coupling of any switch of said plurality to the output circuit.

33. A machine as in claim 32 wherein the sequential coupling means includes a logic circuit having at least one input and means sequentially coupling each switch of said plurality to the logic circuit input, and wherein the governing means includes means responsive to the signal for controlling the logic circuit.

34. A machine as in claim 32 wherein the means pro viding the master control signal includes a bistable circuit and means responsive to the selector switch for setting the bistable circuit.

35. A machine as in claim 32 wherein the means providing the master control signal includes a bistable circuit and means responsive to the time keeping device for resetting the bistable circuit at a predetermined time less than seconds after each minute.

36. A machine as in claim 35 wherein the resetting means includes manually operable means for adjusting said predetermined time.

37. A machine as in claim 32 further including a second manually-operable selector switch having a number of positions equal to the maximum count of the minutes counter, means coupling the minutes counter to the second selector switch, means responsive to the second selector switch for providing a second master control signal, and second means responsive to the second signal for governing the coupling of any switch of said plurality to the output circuit.

38. A machine as in claim 37 wherein the output circuit includes a two state device and means responsive to the two state device for selectively controlling the first and second governing means.

39. A machine as in claim 37 wherein the output circuit includes a two state device and wherein the first and second governing means comprise a first and a second logic circuit each having at least one input, means coupling the first signal to the input of the first logic circuit, means coupling the second signal to the input of the second logic circuit, means responsive to one state of the two state device for enabling the first logic circuit and disabling the second logic circuit, and means responsive to the other state of the two state device for disabling the first logic circuit and enabling the second logic circuit.

40. A machine as in claim 37 wherein the output circuit includes a two state device, a gating circuit, a holding circuit, means including the gating circuit for coupling the two state device to the holding circuit, and means for enabling the gating circuit at a predetermined time less than 60 seconds after the minutes counter provides its maximum count.

41. A machine as in claim 37 wherein the output circuit includes a two state device, a gating circuit, a holding circuit, means including the gating circuit for coupling the two state device to the holding circuit, and means for enabling the gating circuit at a predetermined time less than 60 seconds after each minute.

42. A machine as in claim 1 wherein the output -circuit includes a two state device, a relay having a winding and at least a pair of contacts, means responsive to the two state device for selectively energizing the relay winding, a first and a second electrical receptacle, and means including the relay contacts for selectively energizing the first and second receptacles.

43. A machine as in claim 42 further including a first visual indicator connected in shunt with the first receptacle and a second visual indicator connected in shunt with the second receptacle.

44. A machine as in claim 1 wherein each switch comprises a pair of contacts, at least one contact being moveable, and means resiliently biasing said moveable contact against the other contact.

45. A machine as in claim 1 wherein each switch comprises a pair of normally closed contacts, at least 48. A machine as in claim 1 further including a top wall provided with a plurality of slots adapted to receive business cards, wherein the slots are disposed in a plurality of columns of equal length. 

1. A time reminding machine including in combination a plurality of normally-closed manually-operable switches, a time keeping device, an output circuit, and means responsive to the time keeping device for sequentially coupling each switch to the output circuit, said output circuit providing an output signal upon the coupling thereto of a switch which has been manually operated from its normal closed position to an open position.
 2. A machine as in claim 1 wherein each switch comprises a pair of normally closed spring contacts and a thin insulating member adapted to be inserted therebetween.
 3. A machine as in claim 1 wherein each switch comprises a pair of normally closed spring contacts, the machine further including a Thin insulating member adapted to be inserted between the contacts of a selected pair.
 4. A machine as in claim 3 wherein each group of two adjacent pairs of contacts comprises a centrally disposed U-shaped member, a first finger normally contacting one U leg of said member, and a second finger normally contacting the other U leg of said member.
 5. A machine as in claim 4 wherein each U leg and its contacting finger flare apart adjacent their free ends to guide the insertion of the insulating member therebetween.
 6. A machine as in claim 3 wherein alternate groups of two adjacent pairs of contacts are disposed in alternate planes.
 7. A machine as in claim 1 wherein the time keeping device includes an hour hand mounted on a shaft.
 8. A machine as in claim 7 wherein the sequential coupling means includes a stationary commutator having a plurality of equally spaced conductive segments, means connecting each switch to a corresponding segment, and a brush mounted on said shaft and disposed to contact sequentially the segments of the commutator.
 9. A machine as in claim 7 wherein the sequential coupling means includes a stationary commutator having a plurality of equally spaced conductive segments, and a pair of angularly spaced brushes mounted on said shaft and disposed to contact sequentially the segments of the commutator.
 10. A machine as in claim 7 wherein the number of switches is N and wherein the sequential coupling means includes a pair of brushes mounted on said shaft and having an angular spacing of approximately 180/N* .
 11. A machine as in claim 7 wherein the number of switches is N and wherein the sequential coupling means includes a stationary commutator having N equally spaced conductive segments, each segment subtending appreciably more than 180/N* , and the insulating gap between adjacent segments subtending appreciably less than 180/N* .
 12. A machine as in claim 1 further including time indicia associated with each switch.
 13. A machine as in claim 12 wherein the indicia provide half-hour increments.
 14. A machine as in claim 12 wherein the indicia provide quarter-hour increments.
 15. A machine as in claim 12 wherein the indicia are disposed in two columns of equal length.
 16. A machine as in claim 15 wherein the indicia at the top of the left hand column represents a whole hour in the region from 6:00 to 9:00 and wherein the indicia at the top of the right hand column represents a whole hour in the region from 12:00 to 3:00.
 17. A machine as in claim 1 further including a top wall provided with a plurality of slots adapted to receive business cards.
 18. A machine as in claim 1 further including a top wall provided with a calendar pad bearing time indicia.
 19. A machine as in claim 1 further including a top wall, wherein the switches include manual operating members arranged in columns along the left hand and right hand margins of the top wall and disposed for movement left and right.
 20. A machine as in claim 1 wherein the output circuit includes an aural annunciator and a visual annunciator.
 21. A machine as in claim 1 further including an annunciator, a bistable circuit, means coupling the bistable circuit to the annunciator, means responsive to the output circuit for setting the bistable circuit, a manually-operable spring-loaded switch, and means responsive to operation of said switch for resetting the bistable circuit.
 22. A machine as in claim 1 wherein the time keeping device includes a source of reference frequency, a plurality of cascaded counters, a plurality of display indicators, means coupling the reference source to the first counter of the cascade, and means coupling the final counters of the cascade to the respective display indicators.
 23. A machine as in claim 22 wherein at least four numerical indicators provide a display in hours and minutes.
 24. A machine as in claim 22 wherein at least six numErical indicators provide a display in hours and minutes and seconds.
 25. A machine as in claim 22 wherein two numerical indicators display hours from 1 to 12 and wherein at least one further indicator selectively provides a display of ante and post meridian.
 26. A machine as in claim 22 wherein the last counter of the cascade divides by two and is coupled to an indicator selectively providing the letters A and P, the machine further including an indicator providing a constant display of the letter M.
 27. A machine as in claim 1 wherein the time keeping device includes a first divide-by-ten counter, a second divide-by-six counter, a third counter, means including a source of reference frequency for providing one pulse of fractional second duration each minute, means responsive to each one-per-minute pulse for indexing the first counter, means responsive to the first counter for indexing the second counter, means responsive to the second counter for providing one pulse of fractional second duration each hour, means responsive to each one-per-hour pulse for indexing the third counter, a first and a second manually-operable spring-loaded switch, means responsive to each operation of the first switch for providing a first pulse of fractional second duration, means responsive to each operation of the second switch for providing a second pulse of fractional second duration, means responsive to each first pulse for indexing the first counter, and means responsive to each second pulse for indexing the third counter.
 28. A machine as in claim 27 wherein the means providing the one-per-minute pulses includes a fourth divide-by-ten counter, a fifth divide-by-six counter, means including a source of reference frequency for providing one pulse of short duration each second of time, means responsive to each one-per-second pulse for indexing the fourth counter, means responsive to the fourth counter for indexing the fifth counter, and means responsive to the fifth counter for providing the one-per-minute pulses, the machine further including a third manually-operable spring-loaded switch, means responsive to each operation of the third switch for providing a third pulse of fractional second duration, and means responsive to each third pulse for indexing the fourth counter.
 29. A machine as in claim 27 wherein the third counter divides by 10, the machine further including a two state device and means responsive to the third counter for indexing the two state device.
 30. A machine as in claim 1 wherein the sequential coupling means includes a plurality of logic circuits having at least one input, means connecting each switch to the input of a corresponding logic circuit, and means responsive to the time keeping device for sequentially controlling the logic circuits.
 31. A machine as in claim 30 wherein the time keeping device includes an hours counter and a fractional hours counter, wherein each logic circuit has a second and a third input, and wherein the sequential controlling means includes means coupling the hours counter to the second input of each logic circuit and means coupling the fractional hours counter to the third input of each logic circuit.
 32. A machine as in claim 1 wherein the time keeping device includes an hours counter, a fractional hours counter having a maximum count not less than two nor greater than 30, and a minutes counter having a maximum count not greater than 30 nor less than two, the product of the maximum counts of the fractional hours and minutes counters being equal to 60, and wherein the sequential coupling means includes means responsive to the hours and the fractional hours counters, the machine further including a first manually-operable selector switch having a number of positions equal to the maximum count of the minutes counter, means coupling the minutes counter to the selector switch, means responsive to the selector switch for providing a first master control signal, and first mEans responsive to the first signal for governing the coupling of any switch of said plurality to the output circuit.
 33. A machine as in claim 32 wherein the sequential coupling means includes a logic circuit having at least one input and means sequentially coupling each switch of said plurality to the logic circuit input, and wherein the governing means includes means responsive to the signal for controlling the logic circuit.
 34. A machine as in claim 32 wherein the means providing the master control signal includes a bistable circuit and means responsive to the selector switch for setting the bistable circuit.
 35. A machine as in claim 32 wherein the means providing the master control signal includes a bistable circuit and means responsive to the time keeping device for resetting the bistable circuit at a predetermined time less than 60 seconds after each minute.
 36. A machine as in claim 35 wherein the resetting means includes manually operable means for adjusting said predetermined time.
 37. A machine as in claim 32 further including a second manually-operable selector switch having a number of positions equal to the maximum count of the minutes counter, means coupling the minutes counter to the second selector switch, means responsive to the second selector switch for providing a second master control signal, and second means responsive to the second signal for governing the coupling of any switch of said plurality to the output circuit.
 38. A machine as in claim 37 wherein the output circuit includes a two state device and means responsive to the two state device for selectively controlling the first and second governing means.
 39. A machine as in claim 37 wherein the output circuit includes a two state device and wherein the first and second governing means comprise a first and a second logic circuit each having at least one input, means coupling the first signal to the input of the first logic circuit, means coupling the second signal to the input of the second logic circuit, means responsive to one state of the two state device for enabling the first logic circuit and disabling the second logic circuit, and means responsive to the other state of the two state device for disabling the first logic circuit and enabling the second logic circuit.
 40. A machine as in claim 37 wherein the output circuit includes a two state device, a gating circuit, a holding circuit, means including the gating circuit for coupling the two state device to the holding circuit, and means for enabling the gating circuit at a predetermined time less than 60 seconds after the minutes counter provides its maximum count.
 41. A machine as in claim 37 wherein the output circuit includes a two state device, a gating circuit, a holding circuit, means including the gating circuit for coupling the two state device to the holding circuit, and means for enabling the gating circuit at a predetermined time less than 60 seconds after each minute.
 42. A machine as in claim 1 wherein the output circuit includes a two state device, a relay having a winding and at least a pair of contacts, means responsive to the two state device for selectively energizing the relay winding, a first and a second electrical receptacle, and means including the relay contacts for selectively energizing the first and second receptacles.
 43. A machine as in claim 42 further including a first visual indicator connected in shunt with the first receptacle and a second visual indicator connected in shunt with the second receptacle.
 44. A machine as in claim 1 wherein each switch comprises a pair of contacts, at least one contact being moveable, and means resiliently biasing said moveable contact against the other contact.
 45. A machine as in claim 1 wherein each switch comprises a pair of normally closed contacts, at least one contact comprising a spring member.
 46. A machine as in claim 45 further including a thin insulating member adapted to be inserted between the contacts of a selected pair, wherein the spring member of each switch is provided with a flaring free end to guide the insertion of the insulating member.
 47. A machine as in claim 1 further including time indicia associated with each switch wherein the indicia are disposed in a plurality of columns of equal length.
 48. A machine as in claim 1 further including a top wall provided with a plurality of slots adapted to receive business cards, wherein the slots are disposed in a plurality of columns of equal length. 